/* ============================================================
   Digital Sekho LMS — Stylesheet
   Brand: clean tech blue, learning-focused, Bengali-first
   ============================================================ */

:root{
  --blue:        #2D9CF0;   /* logo blue */
  --blue-deep:   #1565C0;
  --ink:         #0F1B2D;   /* near-black navy */
  --ink-2:       #1c2c44;
  --slate:       #5a6b82;
  --line:        #e6ebf2;
  --bg:          #f6f9fc;
  --card:        #ffffff;
  --gold:        #F5B301;
  --green:       #16a34a;
  --radius:      16px;
  --shadow:      0 10px 30px rgba(15,27,45,.08);
  --shadow-sm:   0 4px 14px rgba(15,27,45,.06);
}

*{ box-sizing:border-box; margin:0; padding:0; }
html{ scroll-behavior:smooth; }
body{
  font-family:'Hind Siliguri','Poppins',system-ui,sans-serif;
  background:var(--bg);
  color:var(--ink);
  line-height:1.6;
  -webkit-font-smoothing:antialiased;
}
a{ color:inherit; text-decoration:none; }
img{ max-width:100%; display:block; }
.container{ width:min(1180px,92%); margin-inline:auto; }

/* ---------- buttons ---------- */
.btn{
  display:inline-flex; align-items:center; gap:8px;
  font-family:inherit; font-weight:600; font-size:.95rem;
  padding:12px 22px; border-radius:12px; border:0; cursor:pointer;
  transition:transform .15s ease, box-shadow .15s ease, background .15s ease;
}
.btn:active{ transform:translateY(1px); }
.btn-primary{ background:var(--blue); color:#fff; box-shadow:0 6px 18px rgba(45,156,240,.35); }
.btn-primary:hover{ background:var(--blue-deep); }
.btn-gold{ background:var(--gold); color:#3a2c00; box-shadow:0 6px 18px rgba(245,179,1,.35); }
.btn-gold:hover{ filter:brightness(1.05); }
.btn-ghost{ background:transparent; border:1.5px solid var(--line); color:var(--ink); }
.btn-ghost:hover{ border-color:var(--blue); color:var(--blue); }
.btn-block{ width:100%; justify-content:center; }
.btn-lg{ padding:15px 30px; font-size:1.05rem; }

/* ---------- google button ---------- */
.btn-google{
  display:flex; align-items:center; justify-content:center; gap:10px;
  width:100%; padding:12px; border:1.5px solid var(--line);
  border-radius:12px; background:#fff; font-weight:600; color:#3c4043;
  cursor:pointer; transition:background .15s, border-color .15s;
}
.btn-google:hover{ background:#f7f9fc; border-color:#cfd8e3; }
.btn-google img{ width:20px; height:20px; }

/* ---------- header ---------- */
.site-header{
  position:sticky; top:0; z-index:50;
  background:rgba(255,255,255,.9); backdrop-filter:blur(10px);
  border-bottom:1px solid var(--line);
}
.nav{ display:flex; align-items:center; justify-content:space-between; height:70px; gap:20px; }
.brand{ display:flex; align-items:center; gap:10px; }
.brand img{ height:40px; width:auto; }
.brand b{ font-size:1.15rem; letter-spacing:-.3px; }
.nav-links{ display:flex; align-items:center; gap:28px; }
.nav-links a{ font-weight:500; color:var(--slate); font-size:.95rem; }
.nav-links a:hover{ color:var(--blue); }
.nav-cta{ display:flex; align-items:center; gap:10px; }
.menu-toggle{ display:none; background:none; border:0; cursor:pointer; }
.menu-toggle span{ display:block; width:24px; height:2px; background:var(--ink); margin:5px 0; border-radius:2px; }
.avatar{ width:38px; height:38px; border-radius:50%; object-fit:cover; border:2px solid var(--line); }

/* ---------- hero ---------- */
.hero{
  position:relative; overflow:hidden;
  background:radial-gradient(1100px 500px at 80% -10%, rgba(45,156,240,.18), transparent 60%),
             linear-gradient(180deg,#fff, var(--bg));
  padding:70px 0 60px;
}
.hero-grid{ display:grid; grid-template-columns:1.05fr .95fr; gap:50px; align-items:center; }
.eyebrow{
  display:inline-flex; align-items:center; gap:8px;
  background:rgba(45,156,240,.1); color:var(--blue-deep);
  font-weight:600; font-size:.82rem; padding:7px 14px; border-radius:50px; margin-bottom:18px;
}
.hero h1{ font-size:clamp(2rem,4.5vw,3.25rem); line-height:1.15; letter-spacing:-1px; }
.hero h1 .hl{ color:var(--blue); }
.hero p.lead{ color:var(--slate); font-size:1.1rem; margin:18px 0 28px; max-width:520px; }
.hero-actions{ display:flex; gap:14px; flex-wrap:wrap; }
.hero-stats{ display:flex; gap:30px; margin-top:34px; }
.hero-stats .num{ font-size:1.6rem; font-weight:700; color:var(--ink); }
.hero-stats .lbl{ font-size:.82rem; color:var(--slate); }
.hero-visual{ position:relative; }
.hero-visual .card-cover{
  border-radius:20px; box-shadow:0 30px 60px rgba(15,27,45,.22);
  transform:rotate(2deg); border:6px solid #fff;
}
.float-chip{
  position:absolute; background:#fff; box-shadow:var(--shadow);
  border-radius:14px; padding:10px 14px; display:flex; align-items:center; gap:10px;
  font-weight:600; font-size:.85rem;
}
.float-chip .dot{ width:10px;height:10px;border-radius:50%; }
.chip-1{ top:18px; left:-18px; }
.chip-2{ bottom:24px; right:-10px; }

/* ---------- sections ---------- */
.section{ padding:64px 0; }
.section-head{ text-align:center; max-width:640px; margin:0 auto 44px; }
.section-head .tag{ color:var(--blue); font-weight:600; font-size:.85rem; letter-spacing:.5px; text-transform:uppercase; }
.section-head h2{ font-size:clamp(1.6rem,3vw,2.3rem); letter-spacing:-.5px; margin-top:8px; }
.section-head p{ color:var(--slate); margin-top:12px; }

/* ---------- course cards ---------- */
.course-grid{ display:grid; grid-template-columns:repeat(3,1fr); gap:26px; }
.course-card{
  background:var(--card); border-radius:var(--radius); overflow:hidden;
  box-shadow:var(--shadow-sm); border:1px solid var(--line);
  transition:transform .2s ease, box-shadow .2s ease;
  display:flex; flex-direction:column;
}
.course-card:hover{ transform:translateY(-6px); box-shadow:var(--shadow); }
.course-thumb{ aspect-ratio:16/10; overflow:hidden; background:var(--ink); }
.course-thumb img{ width:100%; height:100%; object-fit:cover; }
.course-body{ padding:20px; flex:1; display:flex; flex-direction:column; }
.badge{ display:inline-block; font-size:.72rem; font-weight:600; padding:4px 10px; border-radius:50px; }
.badge-ai{ background:rgba(45,156,240,.12); color:var(--blue-deep); }
.badge-mkt{ background:rgba(245,179,1,.16); color:#8a6500; }
.badge-dev{ background:rgba(22,163,74,.12); color:var(--green); }
.course-body h3{ font-size:1.15rem; margin:12px 0 6px; line-height:1.3; }
.course-body .sub{ color:var(--slate); font-size:.9rem; flex:1; }
.course-meta{ display:flex; align-items:center; gap:14px; color:var(--slate); font-size:.82rem; margin:14px 0; }
.price-row{ display:flex; align-items:center; justify-content:space-between; margin-top:6px; }
.price{ font-size:1.35rem; font-weight:700; color:var(--ink); }
.price s{ color:var(--slate); font-weight:400; font-size:.95rem; margin-left:6px; }

/* ---------- audience / features ---------- */
.feat-grid{ display:grid; grid-template-columns:repeat(3,1fr); gap:22px; }
.feat{
  background:#fff; border:1px solid var(--line); border-radius:var(--radius);
  padding:26px; box-shadow:var(--shadow-sm);
}
.feat .ico{
  width:50px;height:50px;border-radius:12px; display:grid;place-items:center;
  background:rgba(45,156,240,.1); color:var(--blue); font-size:1.4rem; margin-bottom:14px;
}
.feat h4{ font-size:1.08rem; margin-bottom:6px; }
.feat p{ color:var(--slate); font-size:.92rem; }

/* ---------- instructor ---------- */
.instructor{ background:linear-gradient(180deg,#fff,var(--bg)); }
.instructor-grid{ display:grid; grid-template-columns:.8fr 1.2fr; gap:46px; align-items:center; }
.instructor-photo{ position:relative; }
.instructor-photo img{ border-radius:20px; box-shadow:var(--shadow); }
.instructor-photo .ring{
  position:absolute; inset:-14px; border:2px dashed rgba(45,156,240,.4);
  border-radius:26px; z-index:-1;
}
.instructor-grid h2{ font-size:2rem; letter-spacing:-.5px; }
.instructor-grid .role{ color:var(--blue); font-weight:600; margin:6px 0 16px; }
.instructor-grid p{ color:var(--slate); margin-bottom:14px; }
.cred{ display:flex; gap:24px; margin-top:20px; flex-wrap:wrap; }
.cred .num{ font-size:1.5rem; font-weight:700; }
.cred .lbl{ font-size:.82rem; color:var(--slate); }

/* ---------- cta band ---------- */
.cta-band{
  background:linear-gradient(120deg,var(--ink),var(--ink-2));
  color:#fff; border-radius:24px; padding:50px; text-align:center;
  box-shadow:var(--shadow); position:relative; overflow:hidden;
}
.cta-band::before{
  content:''; position:absolute; width:300px;height:300px; border-radius:50%;
  background:radial-gradient(circle,rgba(45,156,240,.4),transparent 70%);
  top:-120px; right:-80px;
}
.cta-band h2{ font-size:clamp(1.6rem,3vw,2.2rem); position:relative; }
.cta-band p{ color:#b9c6d8; margin:12px 0 24px; position:relative; }

/* ---------- footer ---------- */
.site-footer{ background:var(--ink); color:#aab8cc; padding:50px 0 26px; margin-top:60px; }
.footer-grid{ display:grid; grid-template-columns:1.4fr 1fr 1fr 1fr; gap:30px; }
.site-footer .brand b{ color:#fff; }
.site-footer h5{ color:#fff; font-size:.95rem; margin-bottom:14px; }
.site-footer a{ display:block; color:#aab8cc; font-size:.9rem; padding:5px 0; }
.site-footer a:hover{ color:var(--blue); }
.footer-bottom{ border-top:1px solid rgba(255,255,255,.1); margin-top:34px; padding-top:20px; text-align:center; font-size:.85rem; }

/* ---------- auth pages ---------- */
.auth-wrap{ min-height:100vh; display:grid; grid-template-columns:1fr 1fr; }
.auth-side{
  background:linear-gradient(150deg,var(--ink),var(--blue-deep));
  color:#fff; padding:54px; display:flex; flex-direction:column; justify-content:center;
  position:relative; overflow:hidden;
}
.auth-side::after{
  content:''; position:absolute; width:380px;height:380px;border-radius:50%;
  background:radial-gradient(circle,rgba(45,156,240,.45),transparent 70%);
  bottom:-150px; left:-100px;
}
.auth-side h2{ font-size:2rem; line-height:1.2; position:relative; }
.auth-side p{ color:#cdd9ea; margin-top:14px; position:relative; }
.auth-points{ margin-top:30px; position:relative; }
.auth-points li{ list-style:none; display:flex; gap:10px; align-items:center; margin-bottom:14px; }
.auth-points .ck{ background:rgba(255,255,255,.15); width:26px;height:26px;border-radius:50%;
  display:grid;place-items:center; flex:none; }
.auth-main{ display:flex; align-items:center; justify-content:center; padding:40px; }
.auth-card{ width:min(420px,100%); }
.auth-card .brand{ margin-bottom:26px; }
.auth-card h1{ font-size:1.6rem; }
.auth-card .muted{ color:var(--slate); margin:6px 0 24px; }
.divider{ display:flex; align-items:center; gap:14px; color:var(--slate); font-size:.85rem; margin:22px 0; }
.divider::before,.divider::after{ content:''; flex:1; height:1px; background:var(--line); }
.field{ margin-bottom:16px; }
.field label{ display:block; font-size:.88rem; font-weight:600; margin-bottom:6px; }
.field input{
  width:100%; padding:12px 14px; border:1.5px solid var(--line); border-radius:12px;
  font-family:inherit; font-size:.95rem; transition:border-color .15s;
}
.field input:focus{ outline:none; border-color:var(--blue); box-shadow:0 0 0 3px rgba(45,156,240,.12); }
.auth-foot{ text-align:center; margin-top:20px; font-size:.92rem; color:var(--slate); }
.auth-foot a{ color:var(--blue); font-weight:600; }
.alert{ padding:12px 16px; border-radius:12px; font-size:.9rem; margin-bottom:18px; }
.alert-error{ background:#fdecec; color:#b42318; border:1px solid #f6cccc; }
.alert-success{ background:#eafaf0; color:#16794c; border:1px solid #c5edd5; }

/* ---------- dashboard ---------- */
.dash{ display:grid; grid-template-columns:250px 1fr; min-height:100vh; }
.sidebar{ background:var(--ink); color:#cdd9ea; padding:24px 16px; position:sticky; top:0; height:100vh; }
.sidebar .brand{ padding:0 8px 24px; }
.sidebar .brand b{ color:#fff; }
.side-link{
  display:flex; align-items:center; gap:12px; padding:11px 14px; border-radius:10px;
  color:#aab8cc; font-weight:500; font-size:.94rem; margin-bottom:4px;
}
.side-link:hover{ background:rgba(255,255,255,.06); color:#fff; }
.side-link.active{ background:var(--blue); color:#fff; }
.dash-main{ padding:30px 34px; background:var(--bg); }
.dash-top{ display:flex; align-items:center; justify-content:space-between; margin-bottom:28px; }
.dash-top h1{ font-size:1.5rem; }
.stat-row{ display:grid; grid-template-columns:repeat(4,1fr); gap:18px; margin-bottom:28px; }
.stat{ background:#fff; border:1px solid var(--line); border-radius:var(--radius); padding:20px; box-shadow:var(--shadow-sm); }
.stat .v{ font-size:1.8rem; font-weight:700; }
.stat .k{ color:var(--slate); font-size:.85rem; margin-top:4px; }

/* ---------- table ---------- */
.panel{ background:#fff; border:1px solid var(--line); border-radius:var(--radius); box-shadow:var(--shadow-sm); overflow:hidden; }
.panel-head{ padding:18px 22px; border-bottom:1px solid var(--line); display:flex; align-items:center; justify-content:space-between; }
.panel-head h3{ font-size:1.1rem; }
table{ width:100%; border-collapse:collapse; }
th,td{ text-align:left; padding:13px 22px; font-size:.92rem; }
th{ background:#f8fafc; color:var(--slate); font-weight:600; font-size:.82rem; text-transform:uppercase; letter-spacing:.4px; }
tbody tr{ border-top:1px solid var(--line); }
tbody tr:hover{ background:#fafcff; }
.pill{ font-size:.75rem; font-weight:600; padding:3px 10px; border-radius:50px; }
.pill-green{ background:#eafaf0; color:#16794c; }
.pill-gray{ background:#eef1f5; color:#5a6b82; }

/* ---------- learn / player ---------- */
.learn{ display:grid; grid-template-columns:1fr 360px; gap:0; min-height:100vh; }
.player-area{ background:#0b1320; color:#fff; padding:0; }
.player-top{ padding:16px 26px; border-bottom:1px solid rgba(255,255,255,.08); display:flex; align-items:center; gap:14px; }
.video-frame{ aspect-ratio:16/9; background:#000; }
.video-frame iframe{ width:100%; height:100%; border:0; }
.lesson-info{ padding:26px; }
.lesson-info h1{ font-size:1.4rem; }
.lesson-info p{ color:#9fb0c7; margin-top:10px; }
.curriculum{ background:#fff; border-left:1px solid var(--line); overflow-y:auto; max-height:100vh; }
.cur-head{ padding:20px 22px; border-bottom:1px solid var(--line); }
.cur-head h3{ font-size:1.05rem; }
.progress-bar{ height:8px; background:var(--line); border-radius:50px; overflow:hidden; margin-top:12px; }
.progress-bar i{ display:block; height:100%; background:var(--green); border-radius:50px; }
.mod-title{ padding:14px 22px; font-weight:600; font-size:.92rem; background:#f8fafc; border-top:1px solid var(--line); }
.les-item{ display:flex; align-items:center; gap:12px; padding:13px 22px; border-top:1px solid var(--line); cursor:pointer; }
.les-item:hover{ background:#fafcff; }
.les-item.active{ background:rgba(45,156,240,.08); border-left:3px solid var(--blue); }
.les-check{ width:22px;height:22px;border-radius:50%; border:2px solid var(--line); flex:none; display:grid;place-items:center; }
.les-check.done{ background:var(--green); border-color:var(--green); color:#fff; }
.les-item .t{ font-size:.92rem; }
.les-item .d{ font-size:.78rem; color:var(--slate); }

/* ---------- course detail ---------- */
.detail-hero{ background:linear-gradient(120deg,var(--ink),var(--ink-2)); color:#fff; padding:56px 0; }
.detail-grid{ display:grid; grid-template-columns:1.4fr .9fr; gap:40px; align-items:start; }
.detail-grid h1{ font-size:2.2rem; line-height:1.2; }
.detail-grid .sub{ color:#b9c6d8; margin:14px 0; font-size:1.05rem; }
.enroll-card{ background:#fff; color:var(--ink); border-radius:20px; box-shadow:var(--shadow); overflow:hidden; position:sticky; top:90px; }
.enroll-card .thumb{ aspect-ratio:16/10; }
.enroll-card .thumb img{ width:100%;height:100%;object-fit:cover; }
.enroll-card .body{ padding:24px; }
.enroll-price{ font-size:2rem; font-weight:700; }
.enroll-price s{ font-size:1.1rem; color:var(--slate); font-weight:400; margin-left:8px; }
.incl{ margin:18px 0; }
.incl li{ list-style:none; display:flex; gap:10px; align-items:center; padding:7px 0; color:var(--slate); font-size:.92rem; }
.incl .ck{ color:var(--green); }
.curriculum-list .mod{ background:#fff; border:1px solid var(--line); border-radius:12px; margin-bottom:12px; overflow:hidden; }
.curriculum-list .mh{ padding:16px 20px; font-weight:600; background:#f8fafc; }
.curriculum-list .li{ padding:13px 20px; border-top:1px solid var(--line); display:flex; align-items:center; gap:10px; color:var(--slate); font-size:.92rem; }

/* ---------- responsive ---------- */
@media (max-width:980px){
  .hero-grid,.instructor-grid,.detail-grid{ grid-template-columns:1fr; }
  .course-grid,.feat-grid{ grid-template-columns:repeat(2,1fr); }
  .footer-grid{ grid-template-columns:1fr 1fr; }
  .auth-wrap{ grid-template-columns:1fr; }
  .auth-side{ display:none; }
  .stat-row{ grid-template-columns:repeat(2,1fr); }
  .learn{ grid-template-columns:1fr; }
  .dash{ grid-template-columns:1fr; }
  .sidebar{ position:static; height:auto; }
  .hero-visual{ order:-1; }
}
@media (max-width:640px){
  .nav-links{
    display:none; position:absolute; top:70px; left:0; right:0; flex-direction:column;
    background:#fff; padding:16px 24px; gap:6px; box-shadow:var(--shadow); border-bottom:1px solid var(--line);
  }
  .nav-links.open{ display:flex; }
  .menu-toggle{ display:block; }
  .course-grid,.feat-grid,.footer-grid,.stat-row{ grid-template-columns:1fr; }
  .cta-band,.auth-main{ padding:30px 22px; }
  .hero-stats{ gap:20px; }
}